Security validators have been known for many years. Typically, such validators are used for the vending of change and/or goods in return for a piece of paper currency. The state of the art of security validators is best shown in U.S. Pat. No. 4,348,656, to ARDAC, INC., of Willoughby, Ohio, the assignee of the instant application. The invention of that patent teaches the use of a microprocessor to implement various tests performed along the note as the same traverses a note path. The microprocessor then determines the authenticity of the paper tendered as a piece of valid currency as a function of data taken along the note path.
Various types of sensors have also become known in the security validator art. Both reflectance and transmissive types of sensors have been used. The instant invention contemplates the utilization of an LED reflectance sensor such as is well known in the art and, accordingly, the specific type of sensor is not presented as being novel apart from the invention as a whole.
Blind people are at a specific disadvantage in handling currency, as compared to coinage. While a learned blind person may readily determine the validity and value of a piece of coinage from its size and weight, such a determination cannot be made as to currency. While the blind may determine from the texture of a piece of paper that it is, indeed, currency, they are still at a loss to determine the denomination of such currency. As is well known, many public buildings have coffee shops or vending stations operated by the blind. With such blind people being at a disadvantage, or at the mercy of the public, in determining the denomination of a piece of currency, there is a need for a security validator capable of communicating with the blind to advise them as to both the validity and denomination of currencies. Such a device would, of necessity, be of small physical size, easy to store and handle, and include means for audibly communicating the necessary information. Further, such a device would need to recognize a plurality of denominations of currency, regardless of the attitude or position at which they are tendered to the device. In other words, the device would need to have the capability of testing a paper bill presented in either one of four postures: face up, face down, forward, or backward.
A security validator for use by the blind would preferably be of a simplistic nature, while being reliable in its sensing and data processing operations. Specifically, the device would need to be able to determine, for example, the difference between a one dollar bill and a five dollar bill, or a twenty dollar bill, it being understood that the blind can often distinguish by texture whether a piece of paper is indeed a piece of currency. To provide such a simplistic security validator, it is necessary that means be provided for assuring a close positional relationship between the currency and the sensor and that further means be provided to assure that the taking of data from the currency begin within the "green" portion of the bill, and not at the margin.